The present invention generally relates to print media and, in particular, to a magnetic printing media for use in laser and inkjet printers.
Magnetic recording media are used to store information such as sound, video images, and computer data. Common magnetic recording media include tapes, disks, drums, cards, and strips and are used in video tapes, audio tapes, computer disks, and cards that store personal information (e.g., credit cards). Magnetic recording media are typically prepared by coating a non-magnetic support with magnetic particles having of pure metals or metal oxides, a technique that is commonly referred to as metal particle technology. The magnetic particles are adhered to the support by a binder or glue. Since the coating contains binder, fewer magnetic particle are present, which reduces the amount of information that can be recorded on the magnetic recording media. As technology progressed, the need for higher capacity magnetic recording media increased. For these applications, metal evaporated technology was developed. In contrast to metal particle technology, the magnetic metal is heated, evaporated in a vacuum, and deposited onto the support. This technique does not require binder and, therefore, the resulting magnetic layer contains more magnetic particles and is able to store more information.
In addition to storing information on magnetic recording media, magnetic particles are used to encode information onto printed documents. As disclosed in U.S. Pat. No. 4,114,032 issued to Brosow et al., magnetic fibers have been used in documents such as paper currency, credit cards, and identification cards to verify the authenticity of the document. Magnetic particles have also been added to printer inks by incorporating the particles into an ink base that includes pigments or dyes, solvents, and water. The magnetic ink is used to verify that the document is an original, as disclosed in U.S. Pat. No. 4,186,944 issued to Pearce. Another common use of magnetic ink is in magnetic image character recognition (MICR) technology, which is used by the banking industry to print information on checks. The printed, magnetic characters identify the issuing bank, the payer=s account number, and routing numbers used by the bank. The magnetic particles in the characters orient an optical device to the location of the information so that the information can be scanned.
However, magnetic inks are not well suited for all applications. For example, magnetic particles are not compatible with all printing processes or inks because the particles precipitate and clog the printer nozzle. In addition, the amount of information that can be magnetically encoded is limited by the amount of magnetic ink printed on the document. The amount of encodable information is further limited because magnetic ink only contains small amounts of magnetic particles. Finally, magnetic ink is easily damaged by water exposure, scratches, or smearing because the ink is printed on an exposed surface of the document.
Use of inkjet magnet sheets are also known in the art. One such example sold by Xerox consists of a magnetic paper that is designed to receive ink from an inkjet printer and be placed on a metal surface, such as a refrigerator, for display of the printed image. These inkjet magnet sheets, however, do not include a magnetically encodable layer of material.
The present invention relates to a magnetic printing media that is used in a printer. The magnetic printing media is comprised of at least three layers, including a base layer, at least one magnetic layer, and at least one ink receptive layer. Magnetically encoded information is recorded onto the magnetic layer(s), while text and graphics are printed onto the ink receptive layer(s). In a preferred embodiment, the magnetic printing media is used to verify the authenticity of a document. In an alternate embodiment, the magnetic printing media is used to record additional information that is not visible and is protected from photocopying.